My PC has 3 hard drives,(I built it myself last year) C has XP with sp2 and all my progs, D had MP3's and a folder called software where I kept any downloaded software and E is used for video editing. When I went to use Pinnacle studio 9 last night it reported that a new patch was available (32 megs) so I downloaded that to the software folder on D and then ran the patch to install. All went well and after a restart I continued using Pinnacle Studio. A while later I went to listen to an MP3 on D drive,to find that windows reported D to be unformatted and thus unusable! No amount of restarts or restoring would change that. Luckily I had a complete back-up on CD ROM so I formatted the drive and reloaded all my stuff. Anyone have any idea why this should happen? Norton and Microsoft spyware report nothing unusual.